Stains on the Screen: Samsung UE55MU6172 Dark Spot Issue, Clouding & Customer Service Response

Hello, on November 29, 2017 I bought a Samsung phone
UE55MU6172 and basically on the first day I noticed a dark spot on a light background. 20180403_2..919.jpg Download (674.21 kB) 20180403_1..505.jpg Download (653.04 kB) 20180403_1..446.jpg Download (474.34 kB) I decided to contact the customer service department, sent photos, described the problem and received the answer:
"
Dear Mariusz,
I will be happy to take care of your case.
Thank you for contacting Samsung Customer Service Center.

Referring to the question of sent photos and their natural heterogeneity of the displayed image, visible especially on uniform backgrounds in the form of brighter spots, is called "Clouding". This phenomenon is an integral feature of the LCD liquid crystal display technology used in your TV set and is a consequence of the impossible to completely eliminate mechanical micro-stresses of the screen, which arise during the production process, and the heating of its structure during operation.
Due to the design of backlight systems, this phenomenon is visible in most LED TV devices. "
Is it really clouding? Can't advertise it?

Clouding is a tough topic. Unfortunately, most complaints are rejected because the phenomenon is an inherent feature of LCD displays. However, when it is visible in normal use (and not in overclocked settings and in a uniform image), you can try to advertise it. My TV also has clouds, but you can't see them while watching.

I don't see it at first glance, but as soon as a lighter background appears, the stain immediately catches my eye, which is very irritating for me.
As for the settings, they are not overclocked, everything is on the standard settings.

Well, the case looks like this:
After visiting a few unauthorized websites and talking to experts, I learned that this is not clouding for sure.
I called Samsung service office again, the guest on the other side kept insisting on his, but I presented my point and finally, after a long conversation, you said that unauthorized services are not taken into account and I need to have written confirmation from an authorized service center that this however, a malfunction of the matrix.
I contacted such a service, I sent the service technician photos, after an hour I called back and found that the led was burned out and there is no clouding because the clouding is visible on a dark background.
Today came replaced the matrix with a new one. The entire operation lasted maybe 30 minutes. Now, on the new matrix, even the image is brighter and more crystalline everything looks, I hope there will be no more such surprises ?